Power-hacksaw.



E. s. BRADFORD, Jn. OM. OLSON. POWER HACKSAW. APFLIOATION FILED .JUNE17I 1910 Patented Oct. 3, 19'11.

@EMM wp Massachusetts UNITED STATES 1;.'afnam".v OFFICE.

EDWARD s. BRADFORD, Ja., or unicorns, MASSACHUSETTS, AND' M'AUm'rzoLsoN, or BRIDGEPORT, coNnEc'rrcU'r; SAID oLsoN Assrenon 'ro SAIDBRADFORD.

POWER-HACKSAW.

Specification of Letters Patent.

Patented Oct. 3, 1911.

voriginal application med september 24, 1909, seriai No. 519,371.Divided and uns application inea :rune 17,

1910. seria; No. 567,532.

To all whom it may co'ncem':

Beit known that we, (l) EDWARD S. BRAD- FORD, Jr., and (2) MAURrrzOLSON, citizens of the United States, residing at (1) Chicopee, countyof Ham den, State of and (2) Bri geport, .county of Fairfield, State ofConnecticut, have in vented an Improvement in' Power-Hacksavvs, of whichthe following is a specication.

This invention relates to certain new and useful improvements in powerhack saws, being 'a division of our pending a plication for patent ledSept. 24, 1909, erial No. 4519,371. v

The invention has for its object the provision of improved means forlifting ,the saw during its return stroke in order to prevent draggingof the teeth upon the work.

A further Objectis to provide means for varying the distance to whichthe saw is raised during the return stroke.

The invention will be hereinafterfully set- A forth ,and particularlypointed out in ythe claims.

In the accompan ing drawings Figure 1 ,iSja plan view o a power hack sawemy bodying our, improvements. Fig. 2 is a side elevation thereof.` Fig.3 is an end viefw lookingvfrom the right in Fig. 2. Fig. 4 is anenlarged view in side elevation, correspondingto Fig. 2, parts beingbroken away I and showlng a changed position of the blade liftingmechanism. Fig. 5 is a detail rear elevation corresponding with Fig 4.Fig. 6 iev-a section on the line 66 Fig. 5.

Referring to the drawings, 10 designates a frame provided with bearings11 supporta shaft 12 on which is mounted adriving pu y. 13 Iwhichreceives power from any suitable source.. Mounted to rotate on a shaft14 isa sleeve 15 provided with a gear wheel 16 adaptedto mesh with apinion 17 carried by the shaft 12. The sleeve 15 is also provided with acam 18 which lies in the inner face of the gear wheel 16, and may beformed integral therewith if desired, (see Figs. 4 and 5).. U on theouter face of the gear wheel'l ,is a s 'de 19 adapted to reciprocate inways 20, and provided with a pm 21. Said pin is -adapted to operativelyengage an operating lever 22 pivotally sup ortedin the frame at 23 andhaving its ee-"end connected" with the saw frame 24 lby meansof a 25.The saw fra-me provided with the usual saw blade 27. Thev slide 19 maybereciprocated in any suitable manner and vthe pin 21 may be connectedwith the operating lever 22in any preferred way. The method illustratedin our nding application, above identified wil be found both convenientand eii'ective, and need not be further described here. Any suitablemeans for clamping the Work may be employed, the device illustratedcomprising relatively adjustable jaws 28.

The bar 26 is rigidly secured at one end to a disk 30 which is in turnsecured to a shaft 31 journaled, in suitable bearings 32 upon the framework. The inner face of the disk 30 is provided with a recess 33 inwhich is located lan outwardly acting orexpanding clampin bear againstthe wa being provided to prevent displacement'of said ring. The ends ofthe clamping ring 34 overlap, the inner end being specifically 34,adapted' to ringl y l of t e recess, bolts 35 designated by 36 and theouter end by 36%v are so timed that `at the end of the forward stroke ofthe saw, the roller 39 will ride up.

on the high portion of cam 18, the efl'ectpf` which is to swing the arm37. Owing to the distance between the pivotal points of said arm to thespring clamping rlng, said ring is ex anded or forced outward, andcaused to grip the wall of the recess 33, locking the ring to the diskand oscillating the latter. The oscillation of the disk `30 swings thearm 26 which carries the saw upward, and retains it inthe raisedposition during the return stroke, at the, end of which the roller willride down onto the low portion of the cam, releasing the grip of thespring clamping ring upon the diskf30, and permitting said disk, the bar26, and the saw to drop to their normal positions an instant before thecommencement of the next forward or operative stroke. The distance towhich the saw is raised during the. return stroke is deter-` mined byadjustment ofthe tension of the l clamping ring 34. This adjustment isef fecte'd by means of a l'screw l.tlgqlnounted in the frame work andbearing against the up- -p'e'i` endof the arm 37.` It will be obvious A.th .t by tighteningup said screw, the grip of tlre ring 34 upon thewall yof the retaining 4recess 33 will be reduced, and consequently`less oscillation .will be im arted lto the disk by the movement of arm3 and'bar 26 upon which the saw frame reciprocates will not be swung ashigh. 'A slight loosening of the screw 41 will increase the grip of thelclamp ing ring 34; upon vthe Wall of the recess 33, thereby increasingthe oscillation of the disk 30 and the lift ofthe saw carrying bar 26.

. gage the wall thereof, an operating arm for said clutch ring, `andmeans for periodically actuating said arm, whereby the disk isoscillated to raise the bar upon the return stroke of the' saw, andmeans for varyingthe period of engagement of said clutch ring and disk.-

2. An improvement in hack saws comprising a-supporting bar, a disk towhichone end of said bar is secured, said disk having a-recess, a sawmounted to reciprocate on said bar, a resilient clutch ring mounted in.said recess and adapted to engage lthe wall thereof, an arm to whicheach end of said clutch ring is secured, said arm being provided Withabeveled portion, means for pe- `incassi riodically operating said arm to'operate the clutch, whereby the disk is oscillated to raise the barupon the return stroke of the saw, and means engaging the beveledportion of said arm for varying the period of engagep ment of saidclutch.

' 3. An improvement in hack saws'comprising a supportin bar, a disk towhich one end of said bar lssecured, said disk having a recess, a sawmountedto reciprocate on said bar, a resilient 'clutch ring mounted insaid recess and adapted t engage the'wall thereof, said ring beingprovided with overlapping ends turned in at an angle with relation tothe body thereof, an operating arm havingl a beveled end and pivotallyconnectedwith both of said ends, a cam for ac-A tuating said arm, landanadjusting screw arranged to engage the beveled end of said arm. y v

4. An improvement in hack saws comprislng a supporting bar, a disk towhich one end-of said bar 1s secured, said disk having a recess, a sawmounted to reciprocate o-n said bar, a resilient clutch ring mounted insaid recessl and adapted to engage the wall thereof, an adjusting screwfor varying the period rof engagement of said clutch ring with saiddisk, and means for periodically operating said clutch, whereby the diskis oscillated to raise the bar upon the. return stroke of the saw.

In testimony whereof we affix our signatures' in presence of thewitnesses.

EDWARD s. BRADFORD, JR. MAURITZ OLSON. Vitnesses for Bradford: GRACE V.DONAHUE, E. F. COLBURN. l/Vitnesses for Olson:

A. M. WoosTER, S. `W. ATHERTON.

